Heat transfer device



D66. 1, 1931. HARTER HEAT TRANSFER DEVICE Original Filed Aug. 7 1922 n n a n n m m m "mu/d IIIIIIIIIIIIIIIIIIIII,IIIIIIIIIIIIIIIII INVENTOR Patented Dec. 1, 1931 PATENT OFFICE ISAAC HARTER, OF NEW YORK, N. Y., ASSIGNOR TO THE BABCOCK d. WILGOX COMPANY,

OF BAYONNE, NEW JERSEY, A CORPORATION OF NEW JERSEY HEAT TRANSFER DEVICE Original application filed August 7, 1922, Serial No. 580,002. Divided and this application filed July 25,

My present invention relates to devices by which heat may be transferred from one gaseous medium to another, and particularly to air heaters in which the temperature of the 5 air is raised by the waste heat in boiler flue gases and the like, such air usually being heated in order to be supplied to support combustion in furnaces or the like.

The present application is a division of my l application Serial No. 580,002, filed August 7, 1922, which has now matured into Patent No. 1,636,958, granted July 26, 1927.

My invention will best be understood from the following description in connection with the annexed drawings, in which Fig. 1 is an elevation, partly in section, of a steam boiler showing in more or less diagrammatic form my novel air heater applied thereto; Fig. 2

is a sectional View of an air heater embodying 50 my invention taken on the line 22 of Fig. 3; Fig. 3 is a section taken on the line 3-3 of Fig. 2; Fig. 4 is a section taken on the line 4-4 of Fig. 3, and Fig. 5 is an enlarged detailed view.

35 Like reference characters indicate like parts in the several views.

In the more or less diagrammatic representation of the application of an air heater shown in Fig. 1, a boiler of the ordinary 50 type has a furnace chamber 11 to which air may be supplied through -a duct 12. The gases from the furnace 11, after passing over the tubes of the boiler, flow through the gas outlet 13 into a gas duct 14 from which it passes through the air heater represented generally in Fig. 1 by the reference character 15, into a gas outlet duct 16 leading to the stack.

The air heater, represented generally by the reference character in Fig. 1, comprises, in the illustrated form shown in the drawings, a plurality of metallic sheets spaced apart to form channels positioned side by side with gas outlet and gas inlet ducts connected m to these channels, so that through one set of alternate channels air will flow in one direction, and through the remaining alternate channels gas will flow in the opposite direction, so that there will be a plurality of streams of each kind of gas flowing through Serial No. 208,082.

channels separated only by heat conducting walls, sothat the heat in the waste gas may readily be transmitted to the air.

In the embodiment illustrated, the gas enters the air heater through horizontal duct 14 and passes into the sides of the channels formed by spaced plates 20, the channels preferably having parallel walls throughout their length except at the ends where each pair of plates is brought together, as best shown in Fig. 5, the portion 29 extends from one plate to the opposite plate 20, and the flange 30 is used to fasten the edges of the plates to the walls of the member which surrounds the channels.

The air, before entering the air heater proper in which the air and gases are caused to flow in opposite directions thereby securing a counterflow, is preferably preheated. In the embodiment of my invention illustrated, a casing or jacket 31 surrounds the air heater proper, and the air enters at the bottom of the casing, as at 311, and flows upwardly between the casing and the heater proper and thence into openings in the sides of the alternate channels as indicated at a, as best shown in Fig. 2, from which it flows downwardly as indicated by the arrows in Fig. 2, to the air outlet 19.

Similarly, the hot gases enter through the .duct 14 into the sides of the alternate channels and flow upwardly, as indicated by the arrows in Fig. 2, to the gas outlet 16.

While the plates 20, forming the channels for the air and gas respectively, are arranged in parallel relation, the ends thereof converge upwardly, so that the flow area for the gases decreases upwardly, whereas the flow area for the air from the inlets 0: increases downwardly. There is, therefore, a decreasing flow area for the gas, and an increasing flow area for the air throughout the air heater proper where there is a eounterflow between the air and gas.

If desired, the flow areas through the several ducts may be arranged so that they will enlarge or decrease approximatel in proportion to the changes in volume 0 the gas or air passing through them due to changes in temperatures of the gases or air in their passage through the ducts by reason of the heattransfer through the walls of the ducts. This arrangement causes the gases and air to flow at substantially a uniform velocity throughout the length of the respective ducts. In the embodiment of my invention illustrated, it will be noted that the channels or ducts for the gases decrease continuously and uniformly from their inlets to the outlets, and that the flow areas for the ducts or channels conducting the air increase continuously and uniformly from the inlets a to the outlet 19.

It will be understood that the construction and application of the heat-transfer device which I have disclosed, can be varied and that the arrangements which I have shown are merely illustrative.

I claim:

1. A heat-transfer device comprising a plurality of channels for the flow of gas and air with metallic walls therebetween through which heat is conducted from the gas to the air, an inlet to and an outlet for gases from one set of channels, an inlet to and an outlet for air from the other set of channels, said inlets and outlets being so arranged as to provide a counterflow for the gases and the air, the channels being constructed and arranged to cause the flow area for one of the fluids to change continuously from the inlet toward the outlet ends, and means independent of convection for producing a flow of air and gas through their respective channels.

2. A heat-transfer device comprising a plurality of channels for the flow of gas and air with metallic walls therebetween through which heat is conducted from the gas to the air, an inlet to and an outlet for gases from one set of channels, an inlet to and an outlet for air from the other set of channels,

said inlets and outlets being so arranged as to provide a counterflow for the gases and the air, the channels being constructed and arranged to cause the flow area for one of the fluids to change uniformly from the inlet toward the outlet ends, and means independent of convection for producing a flow of air} and gas through their respective channe 5.

3. A heat-transfer device comprising a plurality of parallel sheet metal plates spaced apart to form a channel between each pair of plates, an inlet for gases to an outlet for gases from one set of channels, an inlet for air to and an outlet for air from the other set of channels, said plates being constructed and arranged to cause the flow area of the channels for the gases to decrease continuously from the inlet toward the outlet ends and the flow areas for the air to increase continuously from the inlet toward the outlet ends, and means independent of convection for producing a flow of air and gas through their respective channels.

4. A heat-transfer device comprising a plugases and air, the channels being formed to cause the flow areas for the gases to decrease continuously from the inlet toward the out: let ends, and means independent of convection for producing a flow of air and gas through their respective channels.

5. A heat-transfer device comprising a plurality of sheet metal plates spaced apart to form a channel between each pair of plates, one set of alternate channels for conducting gases and the other set for conducting air so that heat is conducted from the gases through the sheet metal plates to the air, an inlet for gases to and an outlet for gases from one set of channels, an inlet for air to and an outletcfor air from the other set of channels, the parts being constructed and arranged to provide a counterflow for the gases and air, the channels being formed to cause the flow for the gases to decrease continuously from the inlet toward the outlet ends, and the flow areas for the air to increase continuously from the inlet toward the outlet ends, and means independent of convection for producing a flow of air and gas through their respective channels.

6. A heat-transfer device comprising a. plurality of channels for the flow of gas and air with metallic walls therebetween through which heat is conducted from the gas to the air, an inlet to and an outlet for gases from one set of channels, an inlet to and an outlet for air from the other set of channels, said inlets and outlets being so arranged as to provide a counterflow for the gases and the air, the channels being constructed and arranged to cause the flow area for one of the fluids to change from the inlet toward the outlet ends, and means independent of convection for producing a flow of air and gas through their respective channels.

7. A heat-transfer device comprising a plurality of channels for the flow of gas and air with metallic walls therebetween through which heat is conducted from the gas to the air, an inlet to and an outlet for gases from one set of channels, an inlet to and an outlet for air from the other set of channels, said inlets and outlets being so arranged as to provide a counterfiow for the gases and the air, the channels being constructed and arranged to cause the flow area for one of the fluids to change from the inlet toward the outlet ends, said heat-transfer device being 1,as4,sss

surrounded by a. jacketed enclosure through which the air flows and in which it is reheated before entering the inlets to sai air channels. t

s 8. A heat-transfer device comprising a plurality of channels for the flow of gas and air with metallic walls therebetween through which heat is conducted from the gas to the air, an inlet to and an outlet for from 10 one set of channels, an inlet to an an outlet for air from the other set of channels, said inlets and outlets being so arranged as to provide a counterflow for the gases and the air, the channels beingconstructed and arranged 15 to cause the flow area for one of the fluids to change continuously and uniformly from the inlet toward the outlet ends, and means independent of convection for producing a flow of air and gas through their respective channels.

ISAAC HARTER.

CERTIFICATE OF CORRECTION.

latent No. 1,834,398; 7 Granted December 1, 1931,'to

ISAAC HARTER.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, line 53, claim 3, after the word "to" insert the word and; same page, line 96, claim 5, after the word "flow" insert the word areas; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 2nd day of February, A. D. 1932.

g M. J. Moore, (Seal) Acting Commissioner of Patents.

1,as4,sss

surrounded by a. jacketed enclosure through which the air flows and in which it is reheated before entering the inlets to sai air channels. t

s 8. A heat-transfer device comprising a plurality of channels for the flow of gas and air with metallic walls therebetween through which heat is conducted from the gas to the air, an inlet to and an outlet for from 10 one set of channels, an inlet to an an outlet for air from the other set of channels, said inlets and outlets being so arranged as to provide a counterflow for the gases and the air, the channels beingconstructed and arranged 15 to cause the flow area for one of the fluids to change continuously and uniformly from the inlet toward the outlet ends, and means independent of convection for producing a flow of air and gas through their respective channels.

ISAAC HARTER.

CERTIFICATE OF CORRECTION.

latent No. 1,834,398; 7 Granted December 1, 1931,'to

ISAAC HARTER.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, line 53, claim 3, after the word "to" insert the word and; same page, line 96, claim 5, after the word "flow" insert the word areas; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 2nd day of February, A. D. 1932.

g M. J. Moore, (Seal) Acting Commissioner of Patents. 

